Motion pictures often use cameras mounted on a wheeled dolly for certain shots. The wheeled dolly travels on a track, similar to a train track in that it comprises two rails mounted on cross members.
Dolly track is often rented instead of owned. Not all shots require a dolly mounted camera so it is often useful to rent dollies and dolly track only for scenes or shoots that require it. Because of this, rental track is often mishandled and damaged by renters. Even when owned, dolly track may become worn and damaged by use. This is a problem because an important aspect of the dolly track is to provide a smooth surface for moving the camera during the shot. Imperfections in the dolly track can result in unwanted vibrations in the camera, degrading the camera shot. Because dolly track is comprised of joined sections of track, there are joints between sections that have the potential for creating breaks or bumps in the track surface that can be transmitted to the camera during use. In addition, the dolly wheels traveling over these joints can make unwanted noise that is transmitted to the scene being recorded.
One prior art solution to dolly track problems is to use tube style tracks to provide a smooth surface for the dolly wheels. Even with a tube track, the joints are susceptible to poor joins, leading to unwanted surface variations. One prior art track solution is described in U.S. Pat. No. 6,435,421.
There are a number of disadvantages of prior art track systems. One disadvantage is that it is not possible to carry joined sections of track without damaging the track and increasing the possibilities of poor joint performance. This requires completely disassembling all track pieces when the track is to be moved. This is a time consuming process and adds to the cost of filmmaking. Another disadvantage of prior art track systems is the changing performance when temperatures change. The tracks lack consistent performance over typically temperature ranges of use. Another disadvantage of prior art tube tracks is the method used for joining the track sections. The methods used often result in a poor joint that interrupts the desired smooth surface of track. Another disadvantage is that metal tracks can bend or be dented. When a track section is bent, it must be leveled before it can be used. Often a great deal of time is spend before operation simply in leveling or straightening track sections.